Virus-associated nucleases: evidence for endonuclease and exonuclease activity in rabbitpox and vaccinia viruses

The endonucleolytic action of a deoxyribonuclease activity in rabbitpox and vaccinia virus was established by change in sedimentation rate of denatured (3)H-lambda deoxyribonucleic acid substrate. The presence of two deoxyribonuclease activities in pox-virus is confirmed. Exo- and endonuclease activities are unmasked by treatment of purified virus with the detergent Nonidet P-40 and further enhanced by treatment of viral "cores" with trypsin.